Saliva as a diagnostic specimen for SARS‐CoV‐2 detection: A scoping review

Abstract

Objectives This scoping review aims to summarize the diagnostic value of saliva assessed from current studies that (1) compare its performance in reverse transcriptase‐polymerase chain reaction testing to nasopharyngeal swabs, (2) evaluate its performance in rapid and point‐of‐care COVID‐19 diagnostic tests, and (3) explore its use as a specimen for detecting anti‐SARS‐CoV‐2 antibodies. Materials and Methods A systematic search was performed on the following databases: Medline and Embase (Ovid), World Health Organization, Centers for Disease Control and Prevention, and Global Health (Ovid) from January 2019 to September 2021. Of the 657 publications identified from the searches, n = 146 articles were included in the final scoping review. Results Our findings showcase that salivary samples exceed nasopharyngeal swabs in detecting SARS‐CoV‐2 using reverse transcriptase‐polymerase chain reaction testing in several studies. A select number of rapid antigen and point‐of‐care tests from the literature were also identified capable of high detection rates using saliva. Moreover, anti‐SARS‐CoV‐2 antibodies have been shown to be detectable in saliva through biochemical assays. Conclusion We highlight the potential of saliva as an all‐rounded specimen in detecting SARS‐CoV‐2. However, future large‐scale clinical studies will be needed to support its widespread use as a non‐invasive clinical specimen for COVID‐19 testing.

Clinical and Analytical Performance of ELISA Salivary Serologic Assay to Detect SARS-CoV-2 IgG in Children and Adults

“…The use of the salivary matrix to detect active SARS-CoV-2 infection is now well established both with the molecular real-time RT-PCR technique and with chemiluminescent enzyme immunoassays in highly automated platforms [ 9 , 10 , 11 ]: it is easy and noninvasive to collect and fast and cost-effective to analyze, allowing for widespread execution of the tests. Moreover, it is suitable for large-scale serial sampling for epidemiological studies and screening tests, since it may be well-accepted as a sampling method also by fragile, geriatric, and pediatric patients [ 12 , 13 ]. Furthermore, the opportunity to measure both antibodies and viral RNA in one single specimen makes saliva a valuable specimen to monitor individual and population SARS-CoV-2 transmission, infection, and seropositivity [ 14 ], in addition to being used for molecular diagnosis for viral RNA detection.…”

Usability and performance of the MicroGEM Sal6830™, an RT-PCR saliva-based point-of-care platform to detect SARS-CoV-2 in primary healthcare settings with non-laboratory trained operators

“…Even after multiple waves of SARS-CoV-2 outbreaks around the world and many more POC in vitro diagnostic devices issued with emergency use authorization by the U.S. Food and Drug Administration, a call for a saliva-based, RT-PCR, POC device has not received a good response [9]. The MicroGEM Sal6830™ SARS-CoV-2 Saliva Test is the first such test with emergency use authorization to respond to this call and in doing so to overcome many of the challenges described here.…”

Clinical and Analytical Performance of ELISA Salivary Serologic Assay to Detect SARS-CoV-2 IgG in Children and Adults

“…The use of the salivary matrix to detect active COVID-19 infection is now well established both with the molecular real-time RT-PCR technique and with chemiluminescent enzyme immunoassays in highly automated platforms [10,11]: it is easy and non-invasive to collect, and fast and cost-effective to analyze, allowing for widespread execution of the tests. Moreover, it is suitable for large-scale serial sampling for epidemiological studies and screening tests, since it may be well-accepted as a sampling method also by fragile, geriatric, and pediatric patients [12][13][14]. Furthermore, the opportunity to measure both antibodies and viral RNA in one single specimen makes saliva a valuable specimen to monitor individual and population SARS-CoV-2 transmission, infection, and seropositivity [15], in addition to being used for molecular diagnosis for viral RNA detection.…”